Meghan Markle and Prince Harry are less than a week away from their royal wedding, and while this should be a happy time, a source tells ET that the couple have "mixed emotions right now" amid a report that Meghan's father, Thomas Markle, is having some health issues.

On Tuesday, Thomas told TMZ that he would not be attending his daughter's nuptials because he has to have surgery on Wednesday morning after suffering a heart attack a week ago. "[The doctors] will go in and clear blockage, repair damage and put a stent where it is needed," he said after telling the website earlier that day that he was looking forward to attending the wedding and walking Meghan down the aisle.

"This is a serious situation. Meghan and Harry are very concerned,” the source tells ET. “Thomas’ health is a private matter and therefore no comments or statements will be made [by the Palace]."

Meanwhile, Meghan's mother, Doria Ragland, was seen heading to the airport in Los Angeles on Tuesday. The source says that Doria is still scheduled to meet Harry's grandmother, Queen Elizabeth II, as well as other members of the royal family.

The source also notes that Meghan, 36, is leaning on her best friend, Jessica Mulroney, for support during this time. On Wednesday, Mulroney was spotted at London's Heathrow Airport with her family.

Earlier this week, Meghan's father made headlines after a Mail on Sunday report featured CCTV footage of what appeared to be Thomas arranging to take paparazzi images with a photographer.

"This is a deeply personal moment for Ms. Markle in the days before her wedding," Kensington Palace said in a statement to ET on Monday following the photo scandal. "She and Prince Harry ask again for understanding and respect to be extended to Mr. Markle in this difficult situation."

"I was told by sources close to Meghan last night that she was utterly heartbroken, that she couldn't believe that this was happening just days before her wedding," Nicholl said. "That she is close to her father, they always had a special relationship, and that she feels that what he did in terms of staging those photographs were never meant with a cruel intention, it was actually meant to present himself in a more positive light. He didn't ever have any understanding or any suspicions that this could have backfired on him as badly as it has done."